G-quadruplexes are emerging targets in cancer research and understanding how diagnostic probes bind to DNA G-quadruplexes in solution is critical to the development of new molecular tools. In this study the binding of an enantiopure NIR emitting [Os(TAP) (dppz)] complex to different G-quadruplex structures formed by human telomer (hTel) and cMYC sequences in solution is reported. The combination of NMR and time-resolved infrared spectroscopic techniques reveals the sensitivity of the emission response to subtle changes in the binding environment of the complex. Similar behaviour is also observed for the related complex [Os(TAP) (dppp2)] upon quadruplex binding.
Near-infrared (NIR) emitters with high two-photon absorption (2PA) cross-sections are of interest to enable imaging in the tissue transparency windows. This study explores the potential of DNA-stabilized silver nanoclusters (Ag -DNAs) as water-soluble two-photon absorbers. We investigate 2PA of four different atomically precise Ag -DNA species with far-red to NIR emission and varying nanocluster and ligand compositions.
As a nonlinear optical phenomenon, upconversion (UC) occurs when two or more low-energy excitation photons are sequentially absorbed and emitted. Upconversion nanomaterials exhibit superior photostability, non-invasiveness, a unique near-infrared anti-Stokes shift, and enhanced tissue penetration capability. However, general upconversion nanomaterials typically utilize visible light (400-700 nm) for excitation, leading to limited tissue penetration, background signal interference, limited excitation efficiency and imaging quality issues due to tissue absorption and scattering.
In recent years, metal halide perovskite-based light-emitting diodes (LEDs) have garnered significant attention as they display high quantum efficiency, good spectral tunability, and are expected to have low processing costs. When the peak emission wavelength is beyond 900 nm the interest is even higher because of the critical importance of this wavelength for biomedical imaging, night vision, and sensing. However, many challenges persist in fabricating these high-performance NIR LEDs, particularly for wavelengths above 950 nm, which appear to be limited by low radiance and poor stability.
Afterglow fluorescence imaging has been extensively assessed in ultrasensitive bioimaging. Since it eliminates the need for real-time excitation light and thereby circumvents the autofluorescence background of tissue, it holds tremendous potential in accurate biomedical imaging. However, current afterglow probes are rare and emit light only in the visible to near-infrared (NIR) range, which is inadequate for imaging.
Objective: To assess the short-term effects of Multiwavelength Photobiomodulation (LumiThera Valeda Light Delivery System) on retinal functional behavior in patients with retinitis pigmentosa (RP).
Materials And Methods: Twelve RP patients (24 eyes) underwent treatment involving nine photobiomodulation (PBM) sessions using the Valeda system, which emits three distinct wavelengths within the yellow (590 nm; 4 mW/cm2), red (660 nm; 65 mW/cm2), and near-infrared (NIR) (850 nm; 0.6 mW/cm2) spectrum.
